The present invention relates generally to a ball hitch adapted to releasably engage a coupling mechanism on a trailer, and more particularly to a folding ball hitch adapted to be mounted in the bed of a pickup truck for releasably engaging a socket coupling of a fifth wheel trailer.
Ball hitches are used in a wide variety of towing applications for towing many different kinds of trailers. Ball hitches may be mounted to vehicle bumpers and/or hitch drawbars, and in some applications mounted in the bed of a pickup truck. A ball hitch which is mounted in the bed of a pickup truck typically releasably engages a coupling socket of a fifth wheel trailer. The ball hitch is usually located near the center of the truck bed directly over the rear axle, so that the weight of the trailer is evenly distributed between the sides of the truck. Because the ball hitch raises above the surface of the truck bed, use of the truck bed for other purposes, such as hauling various items, is impeded.
To overcome the inconvenience of a ball hitch protruding from the center of a pickup truck bed, folding ball hitches were developed which allow the ball to be lowered into an inoperative position below the surface of the truck bed, thus allowing the truck bed to be used for other purposes when not towing a trailer. A cover plate in the truck bed serves to cover the ball when it is in the inoperative position and also maintains the ball in its operative position when the ball hitch is in use. The cover plate prevents the ball from rotating from its operative position to its inoperative position, until the cover plate is moved out of the path of the ball. One such folding ball hitch is disclosed in U.S. Pat. No. 5,755,452, owned by the assignee of the present invention and incorporated herein by reference.
The hitch is typically mounted with the cover plate at an elevation even with or slightly above the bed of the pickup truck. For instance, the folding ball hitch of U.S. Pat. No. 5,755,452 includes a mounting plate which is mounted on top or even with the bed of the pickup truck. The rest of the hitch structure is beneath the bed of the pickup truck. For additional support strength, the underbed portion of the hitch may mount to the frame of the towing vehicle. For instance, underbed rails (disclosed for instance in U.S. Pat. No. 6,533,308, owned by the assignee of the present invention and incorporated herein by reference) may extend laterally underneath the truck bed, supporting the mounting plate from the frame of the towing vehicle. In the inoperative, stowed position, the hitch ball can be retained in an enclosure, with the enclosure being formed by welding side frame plates and a bottom frame plate together and to the mounting plate.
Such ball hitches need to be strong and reliable, while maintaining a relatively low cost. Improvements which increase the strength and/or reliability of the ball hitch, while simultaneously reducing costs such as in manufacturing and assembly, are very beneficial.